Component Carrier With Embedded Filament

Abstract

A method of manufacturing a component carrier. The method includes forming a stack having at least one electrically insulating layer structure and/or at least one electrically conductive layer structure, and embedding a filament in the stack.

Claims

1. A method of manufacturing a component carrier, comprising: forming a stack comprising at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; and embedding a filament in the stack.

2. The method according to claim 1, wherein the method comprises removing the embedded filament partially or entirely out of the stack.

3. The method according to claim 1, comprising at least one of the following features: the method comprises removing at least part of the filament from the stack by pulling the filament out of the stack; the method comprises embedding the filament in the stack so as to form an in-plane trajectory within a plane perpendicular to a stacking direction of the layer structures of the stack; the method comprises embedding the filament in the stack so that the filament is arranged along a three-dimensional, in particular an out of plane, trajectory having at least one section within a stacking plane of the layer structures of the stack and at least one other section perpendicular to the stacking plane of the layer structures of the stack.

4. The method according to claim 2, comprising at least one of the following features: the method comprises covering at least part of an interior wall of the stack, delimited by a channel remaining after removing the filament, by a coating; the method comprises at least partially filling a channel, which remains in the stack after removing the filament, with electrically conductive material, in particular to thereby form an antenna structure; the method comprises at least partially filling a channel, which remains in the stack after removing the filament, with thermally conductive material to thereby form a heat removal structure for removing heat generated during operation of the component carrier; the method comprises guiding a cooling fluid through a channel, which remains in the stack after removing the filament, for removing heat generated during operation of the component carrier; the method comprises configuring a channel, which remains in the stack after removing the filament, for guiding one of acoustic waves, electromagnetic high-frequency waves, and visible electromagnetic waves along the channel; the method comprises promoting removability of the filament out of the stack by at least one of a group consisting of ultrasonic vibrations, and temperature increase.

5. The method according to claim 1, wherein the method comprises configuring a surface of the filament in contact with the stack to be non-adhesive with regard to the material of the stack.

6. The method according to claim 1, wherein the method comprises: forming at least one recess in at least one of the layer structures of the stack; placing the filament in the recess; and connecting the layer structures, in particular by lamination, to thereby embed the filament in the stack.

7. The method according to claim 1, wherein the method comprises: embedding the filament between opposing planar surfaces of two layer structures of the stack, in particular without forming a recess in any of these two layer structures.

8. The method according to claim 1, wherein the method comprises: embedding the filament in the stack, which filament comprises a core covered with a release layer being covered, in turn, by a coating; and removing the core out of the stack while keeping the coating inside of the stack for lining a remaining channel in the stack with the coating.

9. The method according to claim 1, wherein the method comprises removing the embedded filament partially or entirely out of the stack by pulling the filament out of the stack.

10. A component carrier, comprising: a stack including at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; and a filament embedded in the stack.

11. The component carrier according to claim 10, comprising at least one of the following features: the filament comprises or consists of material having poor adhesion properties with regard to surrounding material of the stack; the filament comprises a core covered with a coating made of a material having poorly adhesive properties with regard to surrounding material of the stack; the filament is configured to be removable from the stack, in particular by pulling the filament out of the stack or by decomposing the filament in the stack; the filament comprises or consists of at least one material of the group consisting of polytetrafluoroethylene, a metal, in particular copper or steel, nylon, graphitewax, and silicon; a cross-section of the filament has a shape of a group consisting of a round shape, in particular a circular shape or an elliptic shape, and a polygonal shape, in particular a triangular shape, a rectangular shape, a cross shape or a star shape; a thickness of the filament is in a range between 100 m and 2 mm; a length of the filament in an interior of the component carrier is in a range between 0.5 cm and 10 m; the filament is configured as co-axial cable; the filament is configured as a heat pipe; at least one material of the filament and a material of one of the at least one electrically insulating layer structure and/or of one of the at least one electrically conductive layer structure are identical.

12. The component carrier according to claim 10, further comprising: a component embedded in the stack, wherein the filament is in particular thermally coupled with the component so as to remove heat generated during operation of the component carrier out of the component and/or is electrically coupled with the component so as to transmit at least one of electric signals and electric energy between the component and an exterior of the component carrier.

13. The component carrier according to claim 12, wherein the component is selected from a group consisting of an electronic component, an electrically non-conductive and/or electrically conductive inlay, a heat transfer unit, a light guiding element, an energy harvesting unit, an active electronic component, a passive electronic component, an electronic chip, a storage device, a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface element, a voltage converter, a cryptographic component, a transmitter and/or receiver, an electromechanical transducer, an actuator, a microelectromechanical system, a microprocessor, a capacitor, a resistor, an inductance, an accumulator, a switch, a camera, an antenna, a magnetic element, a further component carrier and a logic chip.

14. The component carrier according to claim 10, comprising at least one of the following features: at least one of the at least one electrically conductive layer structure and the filament comprises at least one of a group consisting of copper, aluminum, nickel, silver, gold, palladium, and tungsten, any of the mentioned materials being optionally coated with supra-conductive material such as graphene; at least one of the at least one electrically insulating layer structure and the filament comprises at least one of the group consisting of resin, in particular reinforced or non-reinforced resin, for instance epoxy resin or Bismaleimide-Triazine resin, FR-4, FR-5, cyanate ester, polyphenylene derivate, glass, prepreg material, polyimide, polyamide, liquid crystal polymer, epoxy-based Build-Up Film, polytetrafluoroethylene, a ceramic, and a metal oxide; the component carrier is shaped as a plate; the component carrier is configured as one of a group consisting of a printed circuit board, and a substrate; the component carrier is configured as a laminate-type component carrier.

15. A component carrier, comprising: a stack having at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; a channel with constant cross-section in the stack, wherein at least part of a trajectory of the channel extends within a plane of the layer structures.

16. The component carrier according to claim 15, comprising at least one of the following features: at least a part of the channel is lined with a coating, in particular a coating selected from a group consisting of an electrically conductive coating, a thermally conductive coating, a coating being reflective for electromagnetic radiation, and a waterproof coating; a cross-section of the channel has a shape of a group consisting of a round shape, in particular a circular shape or an elliptic shape, and a polygonal shape, in particular a triangular shape, a rectangular shape, a cross shape or a star shape; an embedded sensor component connected to the channel so that the sensor component is exposed towards an environment of the component carrier via the channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG. 1 illustrates a cross-sectional view of a pre-form of a component carrier having a filament which is embedded in a cavity according to an exemplary embodiment of the invention.

[0056] FIG. 2 illustrates a cross-sectional view of a component carrier having an embedded filament according to an exemplary embodiment of the invention.

[0057] FIG. 3 illustrates a three dimensionally curved filament embedded in a component carrier according to an exemplary embodiment of the invention.

[0058] FIG. 4 illustrates an image of a component carrier having a channel formed by embedding and subsequently removing a filament in the component carrier according to an exemplary embodiment of the invention.

[0059] FIG. 5 illustrates a cross-sectional view of a component carrier having a channel lined with a tubular coating according to an exemplary embodiment of the invention.

[0060] FIG. 6 illustrates a cross-sectional image of a component carrier having a channel lined with a tubular coating and composed of multiple channel sections extending horizontally and vertically through the component carrier according to an exemplary embodiment of the invention.

[0061] FIG. 7 illustrates a component carrier of the type shown in FIG. 6 and being usable for ducts for high-frequency or acoustic applications.

[0062] FIG. 8 illustrates a component carrier of the type shown in FIG. 6 and being usable for a gas sensor application.

[0063] FIG. 9 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a lined channel with plus-shape.

[0064] FIG. 10 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a lined channel with arc shape.

[0065] FIG. 11 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a lined channel with cross shape.

[0066] FIG. 12 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a lined channel with trapezoid shape.

[0067] FIG. 13 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a channel with star shape.

[0068] FIG. 14 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention having a channel with oval shape.

[0069] FIG. 15 and FIG. 16 illustrate cross-sectional views of component carriers according to exemplary embodiments of the invention with embedded components and a channel-based water cooling of such components.

[0070] FIG. 17 illustrates a cross-sectional view of a component carrier with filament-based wiring structure forming an inductor for a wireless charging application according to an exemplary embodiment of the invention.

[0071] FIG. 18 illustrates a cross-sectional view of a component carrier with horizontally extending lined channel according to an exemplary embodiment of the invention.

[0072] FIG. 19 illustrates a cross-sectional view of a component carrier with a filament having multiple section extending horizontally, vertically and slanted according to an exemplary embodiment of the invention, and being capable of forming a correspondingly shaped channel after removing the filament.

[0073] FIG. 20 illustrates a cross-sectional view of a component carrier with a shielded channel according to an exemplary embodiment of the invention.

[0074] FIG. 21 illustrates a cross-sectional view of a filament according to an exemplary embodiment of the invention.

[0075] FIG. 22 illustrates a cross-sectional view of an electrically conductive filament electrically and mechanically connected to a pad of a component according to an exemplary embodiment of the invention, wherein the component and the filament are preassembled before embedding them in a stack of the component carrier.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0076] The illustrations in the drawings are schematically presented. In different drawings, similar or identical elements are provided with the same reference signs.

[0077] Before, referring to the drawings, exemplary embodiments will be described in further detail, some basic considerations will be summarized based on which exemplary embodiments of the invention have been developed.

[0078] According to an exemplary embodiment of the invention, one or more filaments are embedded in a stack of component carrier material. Subsequently removing the filament(s) by pulling it/them out from the stack may allow the formation of one or more channels or cavities in the component carrier (in particular a printed circuit board, PCB). These channels or cavities can be used for many different applications such as sensors, thermal management, antennas, etc. It is however alternatively also possible to maintain the filament permanently within the component carrier, so that the embedded filament may functionally contribute to the component carrier function. For instance, such a filament may be used for contacting an embedded component, as an embedded optoelectronic light guide, etc.

[0079] By the described manufacturing architecture, it may be possible to form one or more tunnels or channels in a PCB structure in a similar way as an earthworm forms cavities in the earth. According to an exemplary embodiment of the invention, a filament or string may be used for this construction. For example, the string or filament can be made of materials such as polytetrafluoroethylene, metals, nylon, wires, etc. If the filament or string material is selected to have good adhesion to the surrounding component carrier material (in particular PCB epoxy material), then this core material of the filament can be advantageously coated with a further material (which may be denoted as release material) which does not have good or which does not have any adhesion to the epoxy material (for instance polytetrafluoroethylene, graphite (such as DLC, diamond like carbon), wax, silicon, etc.). Descriptively speaking, the filament or string may then work as a temporary or permanently embedded structure in the component carrier. The filament can have substantially any cross-sectional format (for instance triangular, circular, quadrangular, or any other).

[0080] For instance, after a lamination process (which may be accomplished by the supply of mechanical pressure and/or heat), the string can be pulled out of the component carrier leaving behind its cavity as in the above biomimetic example of the wormhole. For example, in order to make the release process more efficient and reliable, ultrasound vibrations and temperature increase can be applied. This can help to break the binding forces between the release layer and the epoxy material. The release process can be carried out at any time of the production of the component carrier, when the component carrier is readily manufactured or after assembly of one or more components on the component carrier.

[0081] The tunnel left behind can be formed to extend in two or three dimensions depending on how the filament or string is placed in the stack up. The tunnel can also be connected to plated through holes and/or laser drilled vias. The filament or string can also be pulled off from holes made on the surface of the component carrier.

[0082] In addition, tunnels and/or a cavity formed by the filament or string can be metallized (for instance can have copper added to its walls), for example via a galvanic copper process forming a sealed structure.

[0083] In one embodiment, the one or more cavities made in the component carrier may extend straight or linear. Techniques with wax may be applied where the hole is formed in the component carrier. A releasing procedure and the freeing of the cavity can be done at the final stage where the component carriers are already cut out of the production panel format.

[0084] Thus, exemplary embodiments of the invention may make it possible to build channels and cavities in the component carrier in any possible format. Advantageously, such a channel can be formed at any production stage of the component carrier. When pulled, the string or filament does not leave any rests in the cavity. To further reduce the effort, one single string or filament can produce the cavity for many different component carriers of a panel.

[0085] In an embodiment, the string or filament can be made of extremely resistant material such as nylon. Another possibility is to use extremely fine strings to produce microscopic channels.

[0086] Exemplary embodiments may also enable active cooling directly in the component carrier via the construction of one or more channels. In other exemplary embodiments of the invention, the embedding of one or more filaments can also be used for high-frequency antennas by allowing air channels for wave propagations. Other exemplary embodiments of the invention may also allow the construction of sensor platforms in an interior of the component carrier. The filament or a cavity formed using such an embedded filament may contribute to the sensor function.

[0087] FIG. 1 illustrates a cross-sectional view of a pre-form of a component carrier 100 having a filament 102 to be embedded in a cavity or recess 114 according to an exemplary embodiment of the invention. The cross-sectional view of FIG. 1 illustrates the pre-form of the component carrier 100 before lamination.

[0088] In the shown embodiment, the component carrier 100 is embodied as printed circuit board (PCB). The component carrier 100 according to FIG. 1 comprises a layer stack 106which is to be connected by laminationcomposed of multiple electrically conductive layer structures 110 and multiple electrically insulating layer structures 108.

[0089] The electrically conductive layer structures 110 may comprise patterned metal layers (such as plated copper and/or patterned copper foils, etc.) and metallic vertical interconnects (not shown in FIG. 1). The vertical interconnects may be formed, for example, by mechanically drilling and/or laser drilling. Correspondingly formed drill holes may then be at least partially filled with electrically conductive material (for instance copper), for instance by a combination of electroless plating and subsequently galvanic plating. In particular, the vertical interconnects are formed by forming holes by laser drilling and subsequently electrically conducting the holes by copper plating.

[0090] The electrically insulating layer structures 108 may comprise laminated layers which may be made of resin (in particular of epoxy resin), optionally additionally comprising reinforcing particles (such as glass fibers or glass spheres). For instance, the electrically insulating layer structures 108 may be made of prepreg or resin-based build-up material. The electrically insulating layer structures 108 also comprise a central base structure 109 with a cavity or recess 114. The base structure 109 may for instance be made of a fully cured dielectric material such as FR4. The layer structures 108, 110 may be connected by lamination to thereby embed the filament 102 in the stack 106. Descriptively speaking, FIG. 1 illustrates a PCB build-up before lamination.

[0091] As shown in FIG. 1, the filament 102 (extending in a direction perpendicular to the paper plane of FIG. 1) with a circular cross-section is embedded in the stack 106. The filament 102 may be made of material having poor adhesion properties with regard to surrounding material of the stack 106. For instance, the filament 102 may be made of steel so that the filament 102 is mechanically strong enabling to be subsequently pulled out of the rest of the component carrier 100. In a corresponding embodiment, a cavity shall be formed at the position of the filament 102 by removing the latter from the stack 106. In the shown embodiment, a cross-section of the filament 102 has a circular shape. A thickness or diameter, D, of the filament 102 may be for example 500 m. A length of the filament 102 in a direction perpendicular to the paper plane of FIG. 1 may be for example 10 cm. Although not shown in FIG. 1, an end of the filament 102 may extend beyond or out of the stack 106 so as to allow pulling out the filament 102 after its embedding out of the stack 106.

[0092] As shown in FIG. 1, the filament 102 may be sandwiched between upper and lower continuous planar sheets of the electrically insulating layer structures 108 (for instance made of an uncured material such as prepreg) and may be accommodated in a central through hole of the central base structure 109 (for instance made of a cured material such as FR4). Such a procedure may be advantageous when the filament 102 has a high thickness or diameter D.

[0093] FIG. 2 illustrates a cross-sectional view of a component carrier 100 having a filament 102 embedded between planar layers 108, 110 according to an exemplary embodiment of the invention.

[0094] In the embodiment of FIG. 2, it may be possible to sandwich the filament 102 directly between two opposing planar surfaces (not shown) of two adjacent layer structures 108 (for instance made of an uncured material such as prepreg) of the stack 106 without previously forming a recess 114 in any of these two layer structures 108. In other words, the central base structure 109 shown in FIG. 1 may be omitted according to FIG. 2. Such an approach allows to particularly simplify manufacture of the component carrier 100 without the need of forming through holes prior to embedding the filament 102, and may be particularly appropriate when the filament 102 has a relatively small thickness or diameter D.

[0095] In the shown embodiment, the filament 102 comprises a cylindrical core 116 (for instance made of steel) covered with a hollow cylindrical coating 112 made of a material (for instance polytetrafluoroethylene) having poorly adhesive properties with regard to surrounding material of the stack 106. By taking this measure, the filament 102 is properly configured so as to be removable from the stack 106 by pulling the filament 102 out of the stack 106 without the risk of tearing of the core 116. A channel 104 (not shown in FIG. 2, see however FIG. 4) may then be formed in the stack 106.

[0096] Hence, FIG. 2 shows a PCB build-up after lamination.

[0097] In another embodiment, the filament 102 may be directly adjacent to one or both of the layers 110. This may allow to directly remove heat on copper layers, so that the filament 102 may be used for example for water cooling.

[0098] FIG. 3 illustrates a three dimensionally curved filament 102 embedded in a component carrier 100 according to an exemplary embodiment of the invention. According to FIG. 3, the filament 102 has been embedded in the stack 106 so as to form a two-dimensional trajectory within a plane perpendicular to a stacking direction of layer structures 108, 110 of the stack 106. Since ends 111 of the filament 102 extend beyond side walls of the component carrier 100, it is possible to pull (in particular manually or machine supported) the filament 102 out of the component carrier 100 so as to form a correspondingly shaped planar channel 104 (see FIG. 4) in an interior of the component carrier 100.

[0099] FIG. 4 illustrates a cross-sectional image of a component carrier 100 having a channel 104 formed by embedding and subsequently removing a filament 102 (not shown in FIG. 4) in the component carrier 100 according to an exemplary embodiment of the invention.

[0100] More precisely, FIG. 4 shows an image of an actually manufactured printed circuit board (PCB) with an approximately 500 m diameter thick and approximately 4 cm long hollow channel 104. Thus, FIG. 4 shows the picture of a real prototype manufactured in the laboratory. A slot or recess 114 was built in a thick PCB core as base structure 109. A wire for microelectronics purposes coated with silicon spray was placed as a filament 102 in the cavity or recess 114 to build the tunnel. In a subsequent procedure, the slot was filled with epoxy material. The structure was placed in an oven at 180 C. for 90 minutes for curing. After curing, the filament 102 was pulled from the rest of the component carrier 100, and the hollow channel 104 was obtained. If desired or required, removal of the filament 102 out of the stack 106 may be promoted by ultrasonic vibrations and/or temperature increase.

[0101] FIG. 5 illustrates a cross-sectional image of a component carrier 100 having a channel 104 lined with a tubular coating 112 according to an exemplary embodiment of the invention. The channel 104 with the coating 112 is embodied as a copper coated tunnel.

[0102] Thus, the shown component carrier 100 has a (in particular hollow) channel 104 with constant circular cross-section in the stack 106. A sidewall of the channel 104 is lined with an electrically conductive and thermally conductive copper coating 112. Descriptively speaking, the coating 112 delimiting channel 104 may form an in-plane plated through hole.

[0103] After embedding a filament 102 with the coating 112 in the stack 106 (in particular using a construction of the filament 102 as shown in FIG. 21 as described below), the component carrier 100 shown in FIG. 5 may be formed by removing a core 116 of the filament 102 from the stack 106 by pulling the core 116 of the filament 102 out of the stack 106. When the core 116 of the filament 102 is removed out of the channel 104, the coating 112 may remain inside the channel 104 and may delimit the channel 104. As an alternative manufacturing method, it may be also possible to remove the entire filament 102 after embedding the same in the stack 106 and to subsequently cover exposed walls of the channel 104 by the copper coating 112.

[0104] FIG. 6 illustrates a cross-sectional image of a component carrier 100 having a channel 104 lined with a tubular coating 112 and composed of multiple connected channel sections (see reference numeral 104) extending horizontally and vertically through the component carrier 100 according to an exemplary embodiment of the invention.

[0105] FIG. 6 shows an example of ducts for water cooling of the component carrier 100. As indicated by arrows 113, water or any other liquid or gaseous cooling medium may be guided through the channel 104 for removing heat out of an interior of the component carrier 100 during operation.

[0106] FIG. 7 illustrates a component carrier 100 of the type shown in FIG. 6 and being usable as ducts for high-frequency or acoustic applications. One or more components 122 may be embedded in the component carrier 100 and/or may be externally connected to the component carrier 100. The components 122 may be for instance sensor components and/or actuator components for applications such as LIFI (light fidelity), WIFI/WLAN (wireless local area network), acoustic applications (for instance for a microphone function or a loudspeaker function), etc. For instance, the channel 104 may be used for the propagation of high-frequency signals, acoustic signals or a resonator function. In particular, the channel 104 formed in the stack 106 by removing the filament 102 may be configured as an acoustic resonator recess.

[0107] FIG. 8 illustrates a component carrier 100 of the type shown in FIG. 6 and being usable for a gas sensor application.

[0108] An embedded sensor component 122 is provided in direct contact with the channel 104 defined by the meanwhile removed filament 102 so that the sensor component 122 is exposed towards an environment of the component carrier 100 via the channel 104 upon removing the filament 102 out of the stack 106. FIG. 8 relates to the example of a duct (in form of channel 104) for gas sensing by gas sensor component 122.

[0109] FIG. 9 to FIG. 14 illustrate cross-sectional views of component carriers 100 with channels 104 formed by removing previously embedded filaments 102 according to exemplary embodiments of the invention. In the embodiment of FIG. 9, a copper-lined (see coating 112) channel 104 with plus-shape is shown. In the embodiment of FIG. 10, a copper-lined (see coating 112) channel 104 with arc-shape is shown. In the embodiment of FIG. 11, a copper-lined (see coating 112) channel 104 with cross-shape is shown. In the embodiment of FIG. 12, a copper-lined (see coating 112) channel 104 with trapezoid-shape is shown. In the embodiment of FIG. 13, a channel 104 with star-shape is shown. In the embodiment of FIG. 14, a channel 104 with oval shape is shown. Many other cross-sectional shapes (for instance a triangular shape) are possible, wherein the respective cross-sectional shape may be selected in accordance with a certain application or function of the component carrier 100. For instance, when the filament 102 forms an embedded heat pipe, a triangular cross-section may be advantageous so that evaporated medium may flow along one or more corners of the triangle.

[0110] FIG. 15 and FIG. 16 illustrate cross-sectional views of component carriers 100 according to exemplary embodiments of the invention with embedded component(s) 122 and a channel 104 (formed by removing a previously embedded filament 102 from the component carrier 100) based water or air cooling of such components 122. A skilled person will understand that water or air cooling may be substituted by cooling using another cooling medium, for instance a liquid gas.

[0111] In the embodiment of FIG. 15, component 122 (for instance a semiconductor die such as a microprocessor) may be embedded in the stack 106 or placed on the surface of the build-up. According to FIG. 16, two components 122 (for instance two semiconductor dies such as a microprocessor and a memory) are embedded in the stack 106 or placed on the surface of the build-up. During operation of the respective component carrier 100, a substantial amount of heat may be generated by the component(s) 122. By the coiled (see FIG. 15) or meandrous (see FIG. 16) configuration of the channel 104 in the region of the respective components(s) 122, a cooling medium guided through the channel 106 may efficiently cooling the respective component(s) 122.

[0112] As an alternative to the configuration of FIG. 15 or FIG. 16, it is also possible to produce the filament 102 of a thermally highly conductive material (such as copper or aluminum) and to dimension the filament 102 sufficiently large so that the thermal coupling of the respective filament 102 with the component(s) 122 allows removing heat generated during operation of the component carrier 100 away from the component(s) 122. In such an embodiment, the filament 102 itself serves as heat removing structure for cooling the components 122.

[0113] FIG. 17 illustrates a cross-sectional view of a component carrier 100 with filament-based wiring structure forming an inductor for a wireless charging application according to an exemplary embodiment of the invention.

[0114] In the embodiment of FIG. 17, the filament 102 may be made of an electrically conductive material such as copper. In view of the wound configuration of the filament 102 according to FIG. 17, the filament 102 fulfils an inductor function. Although not shown in FIG. 17, the coiled type inductor formed by the filament 102 may be accompanied with a magnetic core (for instance made of a ferrite), which can be embedded in the component carrier 100 as an embedded component 122. Alternatively, a filament-based antenna structure embedded in a component carrier 100 may be formed in a corresponding way as shown in FIG. 17.

[0115] As an alternative embodiment, it is also possible to remove a dummy filament 102 out of the component carrier 100 to thereby maintain a channel 104 with coiled shape. It may then be possible to subsequently fill such a channel 104 remaining in the stack 106 after removing the filament 102 with electrically conductive material to thereby form an inductor structure or an antenna structure.

[0116] FIG. 18 illustrates a cross-sectional view of a component carrier 100 with horizontal channel 104 according to an exemplary embodiment of the invention.

[0117] The (in particular hollow) channel 104 is coated with an electrically conductive coating 112, for instance made of copper. The channel 104 is formed by embedding a filament 102 in the component carrier 100 and subsequently removing the filament 102. As an alternative, the filament 102 may be also made of electrically conductive material (for instance made of copper) and may remain permanently inside and form part of the component carrier 100 (for instance to completely fill the channel 104 with copper material).

[0118] As can be taken from FIG. 18, the coating 112 (or alternatively the filament 102, not shown) may be connected to one or more electrically conductive layer structures 110 of the (for instance PCB-type) component carrier 100. FIG. 18 in particular shows, as electrically conductive layer structures 110, vertical interconnect structures (in particular copper filled mechanically drilled through holes and copper filled laser drilled through holes) and patterned copper foils. The electrically conductive layer structures 110 configured as (in particular laser and/or mechanically drilled) vias may function to electrically and/or thermally connect the PCB-type component carrier 100.

[0119] FIG. 19 illustrates a cross-sectional view of a component carrier 100 with a channel 104 having multiple section extending horizontally (see reference numeral 171), vertically (see reference numeral 173) and slanted (see reference numeral 175) according to an exemplary embodiment of the invention.

[0120] The structure according to FIG. 19 shows an embedded filament 102 in the stack 106 which is bent along a three-dimensional trajectory in the stack 106. Different sections of the filament 102 have different angles , , etc. with regard to a vertical direction (in other words, , may denote the respective cavity angle towards the surface normal). Referring to FIG. 19, the orientation of the filament 102 may be selected to reach one or more predefined constraints such as , 0n, etc. After having removed the filament 102 out of the component carrier 100, a three-dimensionally curved cavity or channel 104 maintains.

[0121] FIG. 20 illustrates a cross-sectional view (parallel to an extension direction of a filament 102) of a component carrier 100 with a shielded channel 104 according to an exemplary embodiment of the invention. FIG. 21 illustrates a cross-sectional view of a filament 102 (wherein an extension direction of the filament 102 is perpendicular to the paper plane of FIG. 21) according to an exemplary embodiment of the invention, which can be used advantageously for the embodiment of FIG. 20.

[0122] FIG. 20 shows an embodiment in which a longitudinally central portion of the filament 102 has a coating 112 of copper. Between a core 116 and the coating 112 of the filament 102, a release layer 118 is sandwiched which is non-adhesive. Thus, the core 116 of the filament 102 is covered with the release layer 118 being covered, in turn, by the copper coating 112. As a result, when removing the core 116 with the release layer 118 out of the stack 106 by pulling along pulling direction 115, the coating 112 maintains inside of the stack 106 for lining the remaining channel 104 in the stack 106. By such a procedure, a shielded cavity may be formed by channel 104 surrounded by the copper coating 112.

[0123] FIG. 22 illustrates a cross-sectional view of an electrically conductive filament 102 electrically and mechanically connected to one or more pads 121 of a component 122 according to an exemplary embodiment of the invention. As shown, the component 122 and the filament 102 are pre-assembled before embedding them in a stack 106 of the component carrier 100.

[0124] According to FIG. 22, the electrically conductive filament 102 is electrically coupled with one or more pads 121 of the component 122 so as to transfer electric signals and/or electric energy between the component 122 and an exterior of the component carrier 100. When the component 122 with already electrically connected filament 102 is embedded in the stack 106 (without previous cavity formation according to FIG. 22 or with previous cavity formation, see recess 114 in FIG. 1), a complicated subsequent electric contacting of the component 122 may be omitted.

[0125] It should be noted that the term comprising does not exclude other elements or steps and the article a or an does not exclude a plurality. Also, elements described in association with different embodiments may be combined.

[0126] Implementation of the component carrier is not limited to the preferred embodiments shown in the figures and described above. Instead, a multiplicity of variants are possible which use the solutions shown and the principle according to the disclosed component carrier even in the case of fundamentally different embodiments.